The Norfolk, Va.-based MSC ship is helmed by a civilian master; Knoop had been the most senior naval officer aboard, Navy officials said.

“There was a belief that there was a lack of leadership involvement in the day-to-day operations of the Comfort MTF,” said MSC spokesman Tom Van Leunen, who said the command investigation was prompted by a crew member’s anonymous complaint in mid-June and has concluded.

“When you look at that ship, the admiral [in charge of MSC] has to know that the ship can go from [reduced operating status] and five days later deploying with 1,200 people aboard who will then be under the command of that officer,” Van Leunen explained. “And from MSC’s perspective, [Shannon] was not confident that that would happen.”

Van Leunen said he was not able to provide specifics on command climate problems out of concern for crew members’ privacy.

Knoop, 60, entered service via an Armed Forces Health Professions Scholarship in 1985, according to his online bio. He completed an internship at Naval Medical Center Portsmouth, Va., in 1986, earned his flight surgeon designation in 1987 and began a long series of duty stations that included a 2005 deployment to Afghanistan as the officer in charge of a surgical/shock trauma platoon.

Knoop served as force surgeon for III Marine Expeditionary Force from 2011 to 2012 before taking over on the Comfort, according to his bio. He’s one of four authors listed on the third edition of The Atlas of Emergency Medicine. Military awards include the Legion of Merit and the Bronze Star Medal, according to his bio.

Knoop did not immediately respond to an email and phone message seeking comment Tuesday.